Simulated milk products utilizing vegetable materials have been known for many years. The most common vegetable material used to prepare simulated milk products is a soybean. Two of the most common simulated milk products made from soybeans are soy milk and tofu. Soy milk is a water extract of soybeans which has been found to be nutritionally comparable to cow's milk in most respects. Because soy milk does not contain lactose and has no cholesterol, it is an ideal substitute for cow's milk. Individuals who are lactose-intolerant and on restricted cholesterol intake diets can now be able to drink a product similar to milk without the adverse side effects. Additionally, soy milk is much less expensive and is a more readily available protein source for individuals in developing nations. For these reasons, it is important to solve problems pertaining to production and storage of soy milk.
Unfortunately, the present methods of making soy milk result in a less than optimal dairy milk substitute. Generally, soy milk has a clear, distinct, and unappealing flavor difference and a difference in texture that gives the soy milk a poor and unpleasant "mouthfeel." The poor mouthfeel is a result of cellulosic, proteinaceous and carbohydrate constituents of the soybean. These constituents are known by those skilled in the art as okara. Additionally, the appearance of soy milk manufactured by traditional methods is quite unlike milk in both color and degree of opacity. Dairy milk's appearance as a suspension has not been subject to accurate replication with the vegetable food materials, partially because of the high dispersability of milk solids and low dispersability of vegetable solids in water, wherein such dispersability is the ability to partially dissolve and partially suspend as tiny nonsettling particles, and partially because of the off-yellow, off-brown, or off-green color of the vegetable based liquid.
To combat some of these problems associated with duplicating dairy milk, methods of extracting a milk substitute from soybeans have been improved upon. The most common method to eliminate the adverse characteristics of simulated milk products is to remove the okara during the extraction process. The okara generally comprises approximately 35% of the whole soybean. By removing the okara, this method effectively removes 35% of the nutritional value of the soybean. Furthermore, the removal of the okara has created a considerable demand for waste depositories which will collect okara refuse. Because it is becoming cost prohibitive to continue removing the okara from the soybean extract and to discard the okara, this method has numerous disadvantages.
There have been attempts to eliminate the disadvantages of soy milk in comparison with dairy milk. U.S. Pat. No. 3,941,890 to Drachenberg et al. discloses a method of making soy milk that attempts to utilize the whole soybean. Under this method, it is necessary to first microwave heat the soybeans and then use enzymes and a colloid mill to provide a consistency similar to dairy milk. This method has at least three distinct disadvantages. First, this method requires the soybeans to be heated by a microwave apparatus to degrade the enzymes found in whole soybeans. Second, this method utilizes only enzymes to act upon and liquefy those constituents of soybeans known as okara. It is well known that enzymes are extremely fragile and any heat fluctuations or improper solution conditions can alter and adversely affect the efficiency of those enzymes. Because enzymes are so sensitive, this method is not reliable to produce a consistent soy milk product. Lastly, the method as described by this patent requires a colloid mill to provide a consistent simulated milk product. Colloid mills are typically slow, work only at low volumes and do not consistently provide particles of desired size, the later of which is important for providing a mouthfeel similar to dairy milk.
Yet, in view of rising dairy costs, and of food shortages in parts of the world, a definite need has existed for a low-cost, highly-nutritious product that could be substituted freely for dairy milk. This needs to be accomplished without having to slowly condition people to a completely new taste and beverage appearance. Additionally, this should be accomplished by retaining the nutritional value of the whole soybean and eliminating the waste by-product created by removing the okara from the soy milk extract.